1. Field of the Invention
The present invention relates generally to the field of cordless radiotelephone communication systems, and more specifically to a cordless radiotelephone communication system providing telepoint to telepoint calling between pager equipped handsets.
2. Description of the Prior Art
Telepoint base stations, such as 12, 14, or 16, used in a CT-2 (second generation cordless telephone) communication system 10 as shown in FIG. 1, have previously been designed for outbound calling only, i.e. to handle telephone calls originated by CT-2 handsets, such as 18, 20 or 22 which were placed at the telepoint base stations 12, 14, or 16, respectively. The calls were then routed to a conventional telephone 24 through connections 26a, 26b or 26c established through the public switched telephone network 26. There were at least three main reasons for CT-2 system service providers having established the restrictions on outbound calling only. In the first place, most service providers wanted to keep the telepoint telephone access number (TTAN) of each telepoint base station unpublished in order to reduce the opportunities provided for electronic vandalism. Secondly, even if the telepoint telephone access numbers (TTANs) of each telepoint base station were published, a caller attempting to establish communication with a particular CT-2 handset would in most instances not know which telepoint base station was to be contacted in order to reach a particular handset subscriber, unless some prior arrangement had been made. And thirdly, by allowing calls to the telepoint base stations by callers hoping to contact particular CT-2 handset subscribers, the system service provider would temporarily be deprived of potentially revenue producing telephone channels, because such channels would be more frequently tied up due to the inbound calling which would potentially have little likelihood for call completion, thus restricting the number of outbound calls which could be placed at any telepoint base station.
One approach which had been previously proposed to handle inbound calls to the CT-2 handsets 18, 20 or 22, was to utilize in combination an independent pager and a CT-2 handset. When a caller, calling from a conventional telephone 24, wished to reach a particular CT-2 handset subscriber, the caller would first place a call through a connection 26d established through the public switched telephone network 26, as shown in FIG. 1, to a paging terminal 28 in order to send a data message containing the caller's phone number. The data message was then transmitted by the transmitters 30 (only one of which is shown) throughout the paging system. The caller then had to hang-up and wait for a call-back from the paged CT-2 handset subscriber. The pager-in-handset approach could thus be utilized by a caller to locate any handset anywhere within the coverage area of the associated paging system to provide inbound calling from any phone coupled to the public switched telephone network.
However, such a prior art system as described above, and shown in FIG. 1, would not enable a first CT-2 handset subscriber, located at one of the telepoint base stations, or telepoint locations, to communicate with another CT-2 handset subscriber located at another telepoint location, because such prior art systems did not provide any apparatus or method for communicating between the telepoint base stations. There is a need to provide a method and apparatus for handling calls originated by one CT-2 handset subscriber to another CT-2 handset subscriber. And, such a method and apparatus must be able to function when the second CT-2 handset subscriber is located near a CT-2 telepoint base station, or can be within reach a CT-2 telepoint base station in a reasonably short period of time.